Pump



PUMP

Harry J. Sadler and Ernest E. Cook, Minneapolis, Minn. ApplicationFebruary 21, 1958, Serial No. 489,324

1 Claim. (Cl. 103-42) Our invention relates broadly to pumps; and inparticular, relates to pumps of the type having a release mechanism forby-passing fluid from the outlet to the inlet side of the pump whenexcessive pressure is developed at the pump outlet.

An object of our invention is to provide an improved pump of the classdescribed which is simple, compact, and durable in construction, moresimple and easier to manufacture than any previously known similar pumpstructures, and which is also highly reliable and efficient inoperation.

A further object of our invention is to provide an improved pump of theclass described having an end cap comprising a reduced portion and aflange portion, the former telescoping into an open end of the main bodyportion of the pump to form a side wall of the operating chamber and thelatter being provided with circumferentially spaced openings througheach of which extends a headed bolt; these bolts connect the end caps tothe main body portion of the pump for limited movement toward and awayfrom the pump impeller, which is mounted for rotation in the pumpchamber; and the cap is adjustably and yieldably urged into engagementwith the adjacent end of the impeller.

Ihese and other objects and advantages of our invention will becomeapparent in the course of the following specification and claim,reference being had to the accompanying drawings wherein:

Fig. 1 is a view in plan of our invention with some parts being brokenaway and some being shown in section; and

Fig. 2 is a view partly in vertical section and partly in end elevationtaken substantially on the line 22 of Fig. 1.

Referring with greater particularity to the drawings, wherein like partswill be indicated by the same numeral, our novel and improved pumpcomprises body means 10, which preferably is integrally formed andcomprises the major portion of the pump housing. Body portion defines acylindrical chamber 11 which has one open side and an opposite flat sidewall 12. Body means 10 has circumferentially spaced inlet and outletports 13 and 14, respectively, which open into the pump chamber 11.

A shaft 15 is journalled in a bearing boss 16 in body means 143 andextends generally perpendicular to flat side walls 12 from within thechamber 11 outwardly behind the limits of body means 10. An impeller,indicated in its entirety by the numeral 17, is anchored to the innerend of shaft 15 by any suitable means for common rotation therewith.Impeller 17 is mounted eccentrically within cylindrical chamber 11 forrotation therein on an axis defined by shaft 15. Impeller 17 may be ofthe rotary vane type or the gear type. Preferably, as shown, impeller 17comprises a rotor 18 having circumferentially spaced radially outwardlyopening recesses 19 formed therein, which are parallel to the axis ofrotor 18 and extend throughout the width thereof, and rollers 20 whichare mounted in recesses 19 for limited radial movements 2,765,745Patented Oct. 9, 1956 2 between the bottoms thereof and the cylindricalWall of chamber 11.

We provide a single unitary end cap 21 which is releasable in relationto the body portion 10, to be described in more detail hereinafter. Theend cap 21 is formed with a diametrically reduced portion 22 whichtelescopes into the open end 23 of body means 10 to form the side wall24 of chamber 11. Reduced portion 22 has an annular groove 25 in whichis contained a sealing ring or the like 26. End caps 21 is formed with acircumferentially extended flange 27 having several, preferably four,circumferentially spaced openings 28 extending therethrough. Thecircumferentially extended portion 29 of body means 10 encompassing openend 23 has outwardly opening threaded holes 39 formed therein, one ofwhich is to be aligned with each of the openings 28 in flange 27. Bolts31, each having a head 32 and a threaded end 33, extend through openings28 and are screw-threaded into threaded holes 31) to connect the end cap21 to body means 10 for limited movements toward and away from impeller17. Resilient means comprise several coiled compression springs 34,preferably there are four, one associated with each of the bolts 31.Springs 34 encompass bolts 31 between flange 27 and bolt heads 32 toyieldably urge end cap 21 axially into engagement with the adjacent endof impeller 17. It is clear that the bias exerted by springs 34 may beadjusted by manipulation of bolts 31.

The bias of springs 34, adjusted as aforementioned, under normaloperating conditions maintains end cap 21 in engagement with impeller17, as shown in full lines in Fig 1; however, if the pressure withinchamber 11 increases to a predetermined value, end cap 21 will be movedaxially outwardly away from impeller 17 to the position shown in dottedlines in Fig. l, to permit fluid to be by-passed past impeller 17 fromoutlet port 14 to inlet port 13. The initial tension or bias of springs34 determines the amount of pressure which may be built up withinchamber 11 before axial outward movement of end cap 21 and the resultingpressure release.

Our novel and improved pump, as herein disclosed, has been built andtested and found to accomplish all of the aforementioned objects andadvantages. We have formed a structure Which is extremely simple andcompact and yet efliciently and reliably operative. While we have showna preferred commercial embodiment thereof, it will be obvious to thoseskilled in the art that our invention may be modified by manysubstitutions and equivalents and that this disclosure is intended to beillustrative only; therefore we intend to be limited solely by the scopeof the appended claim.

We claim as our invention:

A pump comprising a casing having an internal axially outwardly openingcylindrical bore defining an operating chamber open at one end andclosed at the other, said casing having inlet and outlet ports formedtherein opening into said chamber intermediate the open and closed endsthereof, a shaft journalled in said casing for rotation and extendinginto said chamber generally normally through the closed end thereof, animpeller anchored to said shaft for common rotation therewith andmounted in said chamber for rotation therein, a single unitary end capclosing the open end of said chamber and releasable in relation to saidcasing, said cap comprising a circumferentially extended radiallyoutwardly projecting flange and a cylindrical reduced portion, saidreduced portion being axially aligned with and received in said bore forlongitudinal movement toward and away from said impeller and having aradially outwardly opening channel formed therein adjacent the inner endthereof, an annular sealing member received in said channel and engagingthe inner surface of said bore, said flange having a plurality ofcircumferentially spaced openings extending axially therethroughradially outwardly of said reduced portion each in alignment with adifferent one of a plurality of outwardly opening internally threadedholes formed in said casing, a plurality of headed bolts each extendingthrough a different one of said openings and screw threaded into saidcasing for maintaining said end cap to said casing for limitedlongitudinal move ments, a plurality of coiled compression springs eachencompassing a ditferent one of said bolts between the head thereof andthe flange of said end cap for yieldably urging said end cap toward andinto engagement with the adjacent end of said impeller; whereby, thebias of said springs may be adjusted by manipulation of said bolts. andupon an increase of the pressure within said chamber above a certainvalue as determined by the bias of said References Cited in the tile ofthis patent UNITED STATES PATENTS 1,675,079 ZisCh June 26, 19281,694,805 Wiltse Dec. 11, 1928 1,870,192 Butler Aug. 2, 1932 2,037,894Grisell Apr. 21, 1936 2,134,153 Seyvertsen Oct. 25, 1938 2,462,732Dusevoir Feb. 22, 1949 2,642,001 Dale et a1 June 16, 1953 FOREIGNPATENTS 36,212 Switzerland Mar. 1, 1906

